Toroidal yoke and core assembly therefor

ABSTRACT

A toroidal yoke having a modified core which contains projecting slewing points whereby the separate and distinct coils of the yoke can be wound as a single coil, thus eliminating the need for stopping the winding machine periodicaly during manufacture. The single coil is after formed into a plurality of separate coils by cutting the wire in the proper locations.

United States Patent 11 1 1111 3,757,224

Fedorko et al. Sept. 4, 1973 [54] TOROIDAL YOKE AND CORE ASSEMBLY2,207,777 7/1940 Blain 335/213 THEREFOR 3,246,l92 4 1966 TOI'SCl'l335/213 x [75] Inventors: Francis A. Fedorko, Saint Marys;

Donald J. Kantner, Emporium; P E G H Franklin A. Metzler, Emporium;"mary xmmer 835 arms I James M. Smith, Emporium, all Of Ammey a ey Pa.

[73] Assignee: GTE Sylvania Incorporated, Seneca Falls, NY.

[57] ABSTRACT [22] Filed: May 1, 1972 PP N04 249,390 A toroidal yokehaving a modified core which contains projecting slewing points wherebythe separate and dis- 52 us. 01. 335/210, 335/213 tine eeile of the Ycan he Wound as a single eeih 51 1m. (:1. H0lf 7/00 thus eliminating theneed for StopPihg the Winding [58] Field of Search 335/210, 213 ehihePeriedieely during manufacture The single is after formed into aplurality of separate coils by cut- [56] References Cited ting the wirein the proper locations.

UNITED STATES PATENTS 3,652,966 3/l972 Meier 335/210 6 Claims, 3 DrawingFigures TOROIDAL YOKE AND CORE ASSEMBLY THEREFOR BACKGROUND OF THEINVENTION This invention relates to deflection yokes for cathode raytubes and more particularly to such yokes which are toroidally wound.Still more particularly, it relates to improvements in the core of theyoke which greatly facilitates winding. It is known to make toroidaldeflection yokes for cathode ray tubes; such yokes comprising a hollow,magnetically permeable core having a plurality of coils of wire woundlongitudinally thereabout. That is, each of the turns of the coils aresubstantially parallel to the longitudinal axis of the core. These yokesgenerally have four distinct and separate coils, two for the horizontaldeflection and two for the vertical deflection; however, windingpatterns having ten or more coils are known. Such yokes have beensemi-automatically wound on a yoke winding machine which basically has awinding head having a closed circular track containing a wire loadedbobbin, the yoke being positioned with the circular track substantiallyin the center of the core. In operation, the bobbin revolves around thecircular track in a vertical plane while the yoke is rotated in ahorizontal plane according to a specific wiring or winding pattern. Inall prior art devices of this type it was necessary, after the windingof a first one of the coils, for the operator to stop the machine, severthe wire, fix the cut end so that it would not be lost (generally bytaping to to the core), index the core to the proper position for thenext winding, and restart the machine. As noted above, the procedure hadto be repeated for each of the coils and resulted in a time-consumingoperation which greatly increased the cost of the yoke.

OBJECTS AND SUMMARY OF THE INVENTION It is, therefore, an object of thisinvention to obviate the disadvantages of the prior art.

It is another object of the invention to enhance the winding of toroidyokes.

It is yet another object of the invention to reduce the cost of windingtoroid yokes.

Still another object of the invention is to increase the speed of whichsuch yokes can be wound.

These objects are accomplished in one aspect of the invention by theprovision of a yoke core or body provided with at least two projectingslewing points strategically placed to enable the winding of the yoke asa single coil which can later be separated by proper cutting of the wireinto the necessary number of separate and distinct coils.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of oneembodiment of the invention;

FIG. 2 is a perspective view of an alternate embodiment of theinvention; and

FIG. 3 is a perspective illustrating the use of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS For a better understanding ofthe present invention, together with other and further objects,advantages and capabilities thereof, reference is made to the followingdisclosure and appended claims in conjunction with the above-describeddrawings.

Referring now to the drawings with greater particularity, there is shownin FIG. 1 a toroidal yoke core 10 of a magnetic permeable material suchas ferrite. The yoke core 10 is capable of being wound with a pluralityof separate and distinct coils and comprises a frustoconical hollow body12 having a top 14, a bottom 16 and an angled wall 18. The wall 18 isprovided with at least two slewing points 20 which are displaced fromone another in predetermined locations. The slewing points 20 arepreferably constructed from a nonmagnetic material, and can be attachedto wall 18 by any suitable method, such as gluing. The configuration ofthe slewing points shown is substantially triangular; however, otherconfigurations such as cylindrical can be utilized. It is important,however, that the slewing points have no sharp edges in contact with thewire coil which could scrape the insulation therefrom.

In FIG. 2 is shown an alternate embodiment of the invention. I-Iereinthere is provided a plastic housing 22 which fits over the body 12 ofcore 10. The housing 22 matches in configuration body 10 and is thenconstructed in two pieces, an upper piece 24 and a lower piece 26. Upperpiece 24 has a flange 28 and an angled wall 30 which fits over wall 18of body 12. Lower piece 26 is also provided with a flange 32 which fitsover bottom 16 of body 12. The two pieces are cemented together with anysuitable plastic cement. In this embodiment slewing points 20 projectfrom wall 30. They can be separate pieces cemented into appropriateslots or can be molded as an integral part of the assembly.

In FIG. 3 is shown a diagrammatic representation of the use of theinvention during the winding of the yoke. The arrow indicates thedirection of rotation of the yoke core 10 for purposes of thisillustration, it being obvious that the rotation is not restricted tothis direction.

After the winding of a first coil has been initiated, as represented bywires 34, the winding continues until the necessary number of turns forthe first coil has been completed. At this point in the prior art, itwould be necessary for the operator to stop the machine, cut the wire,index the yoke core to the position of the next coil, and restart thewinding operation. By utilizing this invention a slew point 20a isprovided at the termination of the first coil and when this point isreached the winding operation is halted (this can, of course, beautomatically controlled) while the yoke core 10 continues being indexedto the start of the next coil. The wire 34 catches on point 20a andslews around the body of the core substantially transverse to the normalwinding direction. When the appropriate location is reached, windingagain commences with wire 34 being snubbed about a second slew point 20bwhich is provided at the beginning of the second coil.

While only two slew points have been described herein, it will beobvious that as many as may be necessary can be utilized.

The use of this invention greatly facilitates the winding of toroidalyokes. Eliminating the starting and stopping operations, as well as thecutting and fixing of loose ends by the operator, increases productionand reduces the cost.

While there have been shown what are at present the preferredembodiments of the invention, it will be apparent to those skilled inthe art that various changes and modifications can be made hereinwithout departing from the scope of the invention as defined by theappended claims.

What is claimed is:

l. A toroidal yoke core capable of being wound with a plurality ofseparate and distinct wire coils, said core comprising: a substantiallyfrusto-conical body having an inner surface and an outer surface, saidouter surface having at least two displaced slewing points incorporatedthereon and projecting therefrom.

2. The yoke core of claim 1 wherein said frustoconical body comprises aferrite material of high magnetic permeability and said slewing pointsare affixed directly thereto.

3. The yoke core of claim 1 wherein said slewing points are affixed toan electrically insulating body of substantially the same configurationas said core, said insulating body fitting over said core.

4. The yoke core of claim 1 wherein said core has a longitudinal axisand said slewing points are displaced from one another both radially andalong said longitudinal axis.

5. The yoke core of claim 2 wherein said slewing points arenon-magnetic.

6. A toroidal yoke for a cathode ray tube comprising: a frusto-conicalmagnetic ferrite body; a non-magnetic, similarly shaped coveringtherefor overlying said body, said covering being provided with at leasttwo displaced apart, projecting slewing points; and a coil formed from asingle strand of wire toroidally wound about said covering, said wire atleast once contacting a first of said slewing points and radiallytraversing said covering to a second one of said slewing points.

1. A toroidal yoke core capable of being wound with a plurality ofseparate and distinct wire coils, said core comprising: a substantiallyfrusto-conical body having an inner surface and an outer surface, saidouter surface having at least two displaced slewing points incorporatedthereon and projecting therefrom.
 2. The yoke core of claim 1 whereinsaid frusto-conical body comprises a ferrite material of high magneticpermeability and said slewing points are aFfixed directly thereto. 3.The yoke core of claim 1 wherein said slewing points are affixed to anelectrically insulating body of substantially the same configuration assaid core, said insulating body fitting over said core.
 4. The yoke coreof claim 1 wherein said core has a longitudinal axis and said slewingpoints are displaced from one another both radially and along saidlongitudinal axis.
 5. The yoke core of claim 2 wherein said slewingpoints are non-magnetic.
 6. A toroidal yoke for a cathode ray tubecomprising: a frusto-conical magnetic ferrite body; a non-magnetic,similarly shaped covering therefor overlying said body, said coveringbeing provided with at least two displaced apart, projecting slewingpoints; and a coil formed from a single strand of wire toroidally woundabout said covering, said wire at least once contacting a first of saidslewing points and radially traversing said covering to a second one ofsaid slewing points.